The RefSerialize package

Read, Show and Data.Binary do not check for internal data references to the same address.
As a result, the data is duplicated when serialized. This is a waste of space in the filesystem
and also a waste of serialization time. but the worst consequence is that, when the serialized data is read,
it allocates multiple copies for the same object when referenced multiple times. Because multiple referenced
data is very typical in a pure language such is Haskell, this means that the resulting data loose the beatiful
economy of space and processing time that referential transparency permits.

Every instance of Show/Read can be an instance of Data.RefSerialize.

This package allows the serialization and deserialization of large data structures without duplication of data, with
the result of optimized performance and memory usage. Since the serialized data is also human readable, It is also
useful for debugging purposes.

The deserializer contains a subset of Parsec.Token for defining deserializing parsers.

the serialized string has the form:

expr( var1, ...varn) where var1=value1,..valn=valueN

so that the string can agree with the haskell syntax.

See demo.hs and tutorial.

in this release:

bug in 0.2.5 corrected: empty lists were written with two indirections (insertVar . insertVar). That caused an error in readp